Allow disabling stencil capabilities for the main screen in love.window.setMode.

--HG--
branch : minor

src/modules/graphics/Graphics.h

@@ -338,7 +338,7 @@ public:
 	 * @param width The viewport width.
 	 * @param height The viewport height.
 	 **/
-	virtual bool setMode(int width, int height, int pixelwidth, int pixelheight) = 0;
+	virtual bool setMode(int width, int height, int pixelwidth, int pixelheight, bool windowhasstencil) = 0;
 
 	/**
 	 * Un-sets the current graphics display mode (uninitializing objects if

src/modules/graphics/opengl/Graphics.cpp

@@ -55,6 +55,7 @@ namespace opengl
 
 Graphics::Graphics()
 	: quadIndices(nullptr)
+	, windowHasStencil(false)
 {
 	gl = OpenGL();
 
@@ -69,11 +70,15 @@ Graphics::Graphics()
 
 		if (window->isOpen())
 		{
-			double w = window->getWidth();
-			double h = window->getHeight();
-			window->windowToDPICoords(&w, &h);
+			int w, h;
+			love::window::WindowSettings settings;
+			window->getWindow(w, h, settings);
 
-			setMode((int) w, (int) h, window->getPixelWidth(), window->getPixelHeight());
+			double dpiW = w;
+			double dpiH = h;
+			window->windowToDPICoords(&dpiW, &dpiH);
+
+			setMode((int) dpiW, (int) dpiH, window->getPixelWidth(), window->getPixelHeight(), settings.stencil);
 		}
 	}
 }
@@ -200,7 +205,7 @@ void Graphics::setViewportSize(int width, int height, int pixelwidth, int pixelh
 	}
 }
 
-bool Graphics::setMode(int width, int height, int pixelwidth, int pixelheight)
+bool Graphics::setMode(int width, int height, int pixelwidth, int pixelheight, bool windowhasstencil)
 {
 	this->width = width;
 	this->height = height;
@@ -1103,6 +1108,9 @@ void Graphics::setScissor()
 
 void Graphics::drawToStencilBuffer(StencilAction action, int value)
 {
+	if (states.back().canvases.empty() && !windowHasStencil)
+		throw love::Exception("The window must have stenciling enabled to draw to the main screen's stencil buffer.");
+
 	flushStreamDraws();
 
 	writingToStencil = true;
@@ -1161,6 +1169,9 @@ void Graphics::stopDrawToStencilBuffer()
 
 void Graphics::setStencilTest(CompareMode compare, int value)
 {
+	if (compare != COMPARE_ALWAYS && states.back().canvases.empty() && !windowHasStencil)
+		throw love::Exception("The window must have stenciling enabled to use setStencilTest on the main screen.");
+
 	DisplayState &state = states.back();
 
 	if (state.stencilCompare != compare || state.stencilTestValue != value)

src/modules/graphics/opengl/Graphics.h

@@ -89,7 +89,7 @@ public:
 	Video *newVideo(love::video::VideoStream *stream, float pixeldensity);
 
 	void setViewportSize(int width, int height, int pixelwidth, int pixelheight) override;
-	bool setMode(int width, int height, int pixelwidth, int pixelheight) override;
+	bool setMode(int width, int height, int pixelwidth, int pixelheight, bool windowhasstencil) override;
 	void unSetMode() override;
 
 	void setActive(bool active) override;
@@ -155,6 +155,8 @@ private:
 
 	QuadIndices *quadIndices;
 
+	bool windowHasStencil;
+
 }; // Graphics
 
 } // opengl

src/modules/graphics/opengl/wrap_Graphics.cpp

@@ -204,7 +204,7 @@ int w_getPixelDensity(lua_State *L)
 int w_setCanvas(lua_State *L)
 {
 	// Disable stencil writes.
-	instance()->stopDrawToStencilBuffer();
+	luax_catchexcept(L, [](){ instance()->stopDrawToStencilBuffer(); });
 
 	// called with none -> reset to default buffer
 	if (lua_isnoneornil(L, 1))